A Validated Stability-indicating Hplc Method for the Determination of Related Substances and Assay of Tolterodine Tartarate

A simple and accurate reverse phase liquid chromatographic method was developed for the determination of related substances, degradants and assay of Tolterodine Tartarate active pharmaceutical ingredient used in the treatment of urinary incontinence. A HPLC method was developed for the separation of related substances, degradants obtained from samples generated after stress degradation and also for the determination of assay of Tolterodine Tartarate. The separation was achieved using a Water X-terra MS C18, 150x4.6, 3.5 um column, mobile phase contains 0.05% TFA in water as mobile phase A and 0.05% TFA in Acetonitrile as Mobile phase B using a binary gradient mode with flow rate at 1.0 ml/min. The sample concentration was 0.5 mg/ml, detection wavelength was 220 nm. The injection volume was 10 μL. The resolution between the critical pair of peaks (Impurity-2 & Impurity-3) was found to be greater than 4.0. The limit of detection (LOD) and limit of quantification (LOQ) of Impurity-1, Impurity-2 and Impurity-3 were 66 ng/ml and 200 ng/ml respectively for 10 μl injection volume. The test solution and mobile phase was observed to be stable up to 24 h after the preparation. The validated method yielded good results of precision, linearity, accuracy, and robustness. The proposed method was found to be suitable and accurate for the quantitative determination related substances, degradants and assay of compound Tolterodine Tartarate active pharmaceutical ingredient.